So far as the key array, the original Duett had 12 buttons per side in a proto-Maccann arrangement, with each side having a full chromatic single octave. It'd be possible to do the same on this Campaign Hayden:
D# F G A B
C D E F# G# A#
That said, I value range more than chromaticity, so I was envisioning something like this for playing in they keys of C and G:
C D E F#
F G A B
C D E F#
Also that's a little more symmetrical and might lay out better.
Since the left-hand of a Duet has larger reeds than the right, would that mean that in theory an end which holds 12 low reeds might hold more than 12 reeds an octave higher? Or is the difference in reed size not significant? I see that in the original Duett the chambers are all the same size, but if Alex is CNC-machining the reedblock of plexiglass, would having differing-size chambers be much harder? If doable, would that allow us to add more buttons to the right side (at a little added cost for more reeds and keywork)?
I've been playing around with the Duettina app, playing tunes I know, song accompaniment, etc and I can certainly make do with 12 a side, three rows of four, as shown. If I could add notes, my top choices would be to add a fourth row of "F G A" to the top of the right-hand side, but again in the simplest case I can work with 12. I've played *much* more limited instruments in my time, so I'm not unduly worried about the limitations of this one, particularly if it's mostly for playing alone, or even easier if I'm using it for chord/drone stuff to accompany my voice.
Speaking of drones, one idea I mentioned to Alex was that if he wanted to try messing with the pre-made McMaster-Carr synthetic 5" square machine bellows, without designing a whole big spiel around it, perhaps those bellows could be used to make a keyless small square concertina, with basic/inexpensive materials, with just four reeds in DAda to serve as a drone box for voice accompaniment? But even with the best of labor/material saving that's probably not the most cost-effective way to replicate an Indian shruti-box for a Anglo-Celtic environment, unless someone was really keen for such a thing. Alternately, one useful way to try out the McMaster might be just using it to build a tuning rig? That way you'd have a rig that didn't tie up any time in making, doesn't wear out over time, etc. Just tossing out some brainstorms (practical or no).
@JimMacArthur: Jim, do you have any photos of your MIDI prototype to share, or are those still close-hold at this stage? Very curious to hear how it's working out, if you feel like updating the MIDI concertina thread in General at some point. Neat stuff happening in the concertina world these days! Are we in perhaps the most innovative period of concertina history since the Interwar Years?
Edited by MatthewVanitas, 28 September 2015 - 09:17 AM.